1. Field the Invention
This invention relates to a laparoscopic defogging apparatus. More specifically, it relates to a defogging apparatus wherein the lens and end portion of a laparoscope are immersed prior to use in a heated sterile fluid contained in a hand held receptacle.
2. Description of the Prior Art
It is well known to surgeons who routinely use endoscopes or laparoscopes that fogging of the lens occurs during a medical examination due to the differences in temperature between the scope and the living body in which the laparoscope is inserted. Fogging typically occurs when the lens of the end portion of the laparoscope is cold enough to condense moisture in the immediate vicinity of view such as when a laparoscope at room temperature (i.e., 68.degree. F.) is placed in the vicinity of warm moist tissue. The relatively large metallic mass of the barrel of the laparoscope keeps the laparoscope lens at a cool temperature for an extended period of time even though the laparoscope is in contact with the warm surrounding tissue during examination.
A variety of solutions have been proposed for the above problem. One solution, as set forth in Williams, III et al., U.S. Pat. No. 5,237,984, is to provide a separate sheath member 10 which provides thermal insulation that creates a desirable thermal gradient between the endoscope lens 38 and the endoscope lens cover 14. The endoscope lens cover portion 14 can thus be warmed by the body relatively quickly to the temperature of the viewing surroundings. Williams also suggests the application of a known anti-fog component in the resin used to form the lens cover 14, or on to the cap section 16 during manufacture. While such a method may provide some thermal insulation, the proposed solution does not address the cause of the problem.
Masterson et al., U.S. Pat. No. 5,392,766, discloses the provision of a separate cleaning element which allows for in situ cleaning during a surgical procedure. Such a solution, while effective, requires replacement of existing laparoscopes and endoscopes which are extremely costly.
Others have suggested cleaning the lens by flushing with various cleansing solutions (see U.S. Pat. Nos. 5,225,001; 4,132,227; 5,167,220; 3,980,078; and 5,290,168) or by flushing with a gaseous flow (see U.S. Pat. Nos. 4,760,840 and 3,941,120). Finally, Soviet Union reference 1618-399A1 discloses a laser catheter which includes a complex cooling system.
None of the above described patents provide a solution to the problem but rather, by complex and expensive methods, merely attempt to minimize the effects of the problem.